558 



APPENDIX. 



This brain-fat was again analysed, and found to be composed 

 as follows : 



Hence it follows that the grey substance contains less fat than 

 the white, and that the fat is here replaced by water : and further, 

 that the cerebric acid, and to a certain extent the cholesterin, 

 preponderate in the white substance. 



VII. In the analyses of various parts of the brain of three 

 insane persons he was unable to detect any striking chemical 

 peculiarity. 



VIII. We give his analyses of the brain of the human embryo 

 at different stages, and of that of a child aged 6 months. 



From these and similar observations on the lower animals 

 (dogs, cats, pigs, horses, goats, and cows), it appears that the 

 amount of fat in the brain of the foetus is far less than in that of 

 the adult individuals, the difference being made up by an excess of 

 water. The great and sudden augmentation of fat towards the end 

 of foetal existence, and shortly after birth, is a fact of much physio- 

 logical interest. 



